False PT/INR Results May Appear for Some Patients
Alere has issued a voluntary correction to users of the Alere INRatio and INRatio 2 PT/INR Monitor system of certain medical conditions that should not be tested with the system (INRatio Monitor INRatio 2 Monitor and INRatio Test Strips).
Certain medical conditions may result in an INR result that is clinically significantly lower than a result using a laboratory method (reference INR). The system should not be used in patients with:
- Anemia of any type with hematocrit <30%
- Any conditions associated with elevated fibrinogen levels including:
- Acute inflammatory conditions (eg, acute viral or bacterial infections such as pneumonia or influenza)
- Chronic inflammatory conditions (eg, rheumatoid arthritis, Crohn's disease, ulcerative colitis, infectious liver diseases such as hepatitis, or inflammatory kidney diseases such as diabetic nephropathy and glomerulonephritis).
- Severe infection (eg, sepsis)
- Chronically elevated fibrinogen for any reason
- Hospitalized or advanced stage cancer or end stage renal disease patients requiring hemodialysis.
- Any bleeding or unusual bruising, clinically observed or reported by the patient.
In these cases, patients should have their INR and warfarin therapy monitored by a laboratory INR method. To obtain the most accurate results, healthcare professionals and patient self-testers are also recommended to do the following:
- Patients should have periodic verification of their INR using a laboratory INR method.
- If a significantly discrepant low result on the INRatio and INRatio 2 monitor system vs. plasma-based laboratory INR method occurs, patient should immediately be transitioned to an alternative method for monitoring their INR and warfarin therapy.
- Significant discrepancy in INR results may delay decision to reverse a supratherapeutic INR level following the established guidelines for monitoring warfarin therapy.
- Take caution when the incorrect INR result is within the therapeutic range but the actual value is supratherapeutic, (eg, when the actual INR value is 6 or greater).
- Patients should be tested to confirm that their hematocrit falls within the 30–55% range.
The device concerns have been reported to the Food and Drug Administration, and Alere is investigating into these events.
For more information call (877) 929-2579 or visit INR-Care.com.